chore: replace stale draft with canonical ts-TEMPLATE form for ts-homepage

- Replace alternate template form (with {{YOUR_TAILSCALE_AUTHKEY}}, sys_module
  cap, hardcoded homepage.damconsulting.net serve.json) with the canonical
  ts-TEMPLATE pattern: Tailscale sidecar + Homepage, both via network_mode
- Use named volume for config dir; default settings/services/bookmarks/widgets
  files included as starting points for the user to customize
- Add SECURITY.md and proper .gitignore (incl. Homepage's auto-generated
  custom.css/custom.js/docker.yaml/kubernetes.yaml/proxmox.yaml stubs +
  logs/)
- serve.headscale.json now uses the actual MagicDNS base domain
  (homepage.damconsulting.net) so the user has a working starting point
  to edit, not a {{service}} placeholder that doesn't resolve
- Verified: dashboard renders at homepage.damconsulting.net

homepage/config/services.yaml

@@ -0,0 +1,35 @@
+---
+# Homepage services: https://gethomepage.dev/configs/services/
+# Edit to add your actual ts-* services running on the tailnet.
+# Each service is a link on the dashboard. Point entries to actual tailnet URLs.
+
+- DAM Services:
+    - Vikunja:
+        href: http://{{service}}.yourdomain.com
+        description: Task management
+        icon: vikunja
+    - BookStack:
+        href: http://{{service}}.yourdomain.com
+        description: Documentation wiki
+        icon: bookstack
+    - Uptime Kuma:
+        href: http://{{service}}.yourdomain.com
+        description: Service monitoring
+        icon: uptime-kuma
+    - Focalboard:
+        href: http://{{service}}.yourdomain.com
+        description: Kanban boards
+        icon: focalboard
+    - Shiori:
+        href: http://{{service}}.yourdomain.com
+        description: Bookmark manager
+        icon: shiori
+    - FreshRSS:
+        href: http://{{service}}.yourdomain.com
+        description: RSS reader
+        icon: freshrss
+    - Stirling PDF:
+        href: http://{{service}}.yourdomain.com
+        description: PDF tools
+        icon: stirling-pdf
+